In the production of copper foil, a continuous sheet of foil is formed by an electrodeposition process. The continuous foil produced is typically wound into a roll on an elongated spindle having distal ends which extend beyond the roll for handling purposes. It is not unusual for such rolls to be seven (7) feet or more in length and several feet in diameter. In this respect, large rolls of foil are much like rolls of paper produced in a paper mill. As will be appreciated, a roll of copper foil of such dimensions is nearly equal in weight to a solid piece of copper of similar size. Due to its weight, such a roll is typically moved by a crane system using some form of hook arrangement to grasp the exposed distal ends of the spindle. Such hook arrangements generally require some manual involvement to either secure the hook to the spindle ends, or to remove the hook therefrom once the roll has been moved. Complicated remotely controlled systems utilizing mechanical or electrical actuating elements are also known for accomplishing essentially the same purpose.
The present invention overcomes the foregoing problems and provides an arresting device which will automatically secure itself to a cylindrical portion of a workpiece to permit movement of such workpiece and which will automatically release itself from the workpiece when the workpiece is resupported, the lifting device being operable without human intervention and without mechanical or electrical actuating devices.